The present invention relates to a filter for an internal combustion engine, and more particularly to a filter having an additive dispensing device that dispenses additive into a motor fluid in response to changes in temperature of the motor fluid, such as when the engine is turned on.
Motor oils have detergent or dispersant additives configured to suspend minute particles of soot in the oil, such that the oil carries the soot particles to the filter for removal from the oil. The soot is produced from the incomplete combustion of fossil fuel, which if left in the engine can lead to the formation of sludge and acids. The detergents are particularly beneficial for diesel engines, which are commonly known for producing significant amounts of soot. Other known beneficial additives are basic conditioners, corrosion inhibitors, metal deactivators, antioxidants, friction modifiers, oil stabilizers, pour point depressants, viscosity index improvers, anti-wear agents, extreme pressure additives, alkaline additives, and combinations of the above.
The additives undergo thermal and mechanical degradation. For example, engine heat generated by a significant amount of stop-and-go driving breaks down the additives. Further, the oil eventually becomes so saturated with soot particles that the additives become depleted and cannot carry any more soot in the oil. In both examples, the engine may become unprotected from the formation of sludge and other related problems.
Accordingly, it is desirable to provide an additive dispensing device that is configured to regularly dispense additive into a motor fluid over a period of time, such that the device prolongs the useful life of the fluid. It is further desirable to provide a thermally activated additive dispensing filter having an additive dispensing device that removes soot particles from motor oil over a longer period of time, as compared with conventional filters.